Process for the manufacture of organic acids, especially acetic acid.



. UNITED STATES PATENT OFFICE.

EUGEN GALI'IZENSTEIN AND MARTIN MUGDAN, OF NUREMBEBG, GERMANY, ASSIGN- OBS TO CONSORTIUM FU'R ELEKTROCHEMISCHE INDUSTB-IE G. M. B. H. OF NUBEK- BEBG, GERMANY.

PROCESS FOR THEMANUFACTURE OF ORGANIC ACIDS, ESPECIALLY ACETIC ACID.

1 ,1? 9,420. No Drawing.

To all whom it may concern Be it known that we, EUGEN GALITZEN- s'rnm, subject of the Emperor of Austria- Hun ary, and MARTIN MUGDAN, subject of the xerman Emperor, residing at Nuremberg, Bavaria, Germany, have invented certain new and useful Improvementsin Processes for the Manufacture of Organic Acids, Especially Acetic Acid, of which the following is a specification.

The reaction between acetaldehyde and oxygen only takes vplace very slowly under ordinary conditions so that it may be considered as impossible to prepare acetic acid technically by the interaction of oxygen and acetaldehyde without special precautions. In order to carry out this reaction it has therefore been proposed to employ oxygen under pressure. Such a process is not only attended with considerable difficulties in working, but also with danger of explosion.

Another process for transforming acetaldehyde to acetic acid by oxygen has been described in British Patent No. 17424 of 1911 (J ohnson). In this process the acetal-, dehyde could be rapidly oxidized onl if excess of acetic acid were previously ad ded thereto or excess of acetic anhydrid, trichloracetic acid, etc. Moreover in this process it was necessary to operate at a temperature higher than ordinary atmospheric temperatures.

According to the present invention it has been found that it is possible to attain a transformation of acetaldehyde to acetic acid by means of oxygen without pressure at ordinary temperatures and in such manner that the reaction proceeds quite fairly, when small quantities of manganese compounds are added to the aldehyde as catalysts. The action of the manganese compounds is quite specific. The initial absorption of oxy en by the acetaldehyde can indeed be acce erated to some extent also by compounds of other metals such as for instance of chromium, vanadium, iron, cerium, uranium, etc., but in this case there always result considerable uantities of per-acetic acid according to t e equation CH,CHO+O,=CH CO,H. This acid is capable of decomposing with the aldehyde still rapidity. However, in contradistinctionto Specification of Letters latent.

present with explosive Patented Apr. 18, 1916.

Application filed July 25, 1918. Serial No. 781,188.

the above mentioned catalysts, manganese compounds possess the property not only of catalytically accelerating absorption of oxygen by acetaldehyde, but also the reduction to acetic acid of the per-acetic acid first formed, according to'the equation CH,.CO,H+CH,.CHO=2CH,.CQ,H. Thus it is only by the aid ofmanganese compounds that it is possible to oxidize acet- I aldehyde to acetic acid by oxygen smoothly and without danger.

Example: A vessel of. pure aluminium rovided with'stirring gear and a cooling acket is charged with 300 kilos of pure aoetaldehyde and 2 kilos of powdered manganese acetate, and a current of dry oxygen is led in. By the action of the oxygen the manganese acetate first dimolves in the acetaldehyde giving a brown coloration; this solution now energetically absorbs oxygen. The heat of reaction which is evolved is absorbed by vigorous external cooling by means of running water. The only by-product isa small lkuantity of carbon di-oxid which is blown 0 either from time to time,

or continuously.- The absorption of oxygen is complete after from ten to twenty hours.

In this way a high percentage acetic acid is directly obtained which can be separated by distillation both from the small quantity of unchanged aldehyde and from'the manganese compound.

Other compounds of manganese may be employed instead of manganese acetate with the same success. For example manganese formiate, butyrate, benzoate, lactate orpotassium permanganate, calcium permanganate and various other compounds. these cases a brown solution of manganese compound in acetaldehyde is roduced first in which solution we believe t e manganese compound to be in colloidal form. Gases containing oxygen such as atmospheric air may be used instead of pure oxygen, but in this case care must bef taken that the acetaldehydewhich is carried away by the unabsorbed portion of the gas 6. g. tkenitrogen) is recovered in suitable absorption apparatus.

It will be understood that in carrying out this process, instead of using purealdehyde treated with manganese compounds, the

aldehyde may also be employed dissolved In all .for example in acetaldehyde itself.

in other liquids, for example acetic acid. Finally the manganese compounds may also be employed in conjunction with other catalysts such as for example compounds of chromium or vanadium which accelerate the absorption of oxygen i. e. the primary formation of the per-acid.

Beyond employing the manganese compounds in the powdered form, or adding them dissolved in acetaldehyde, it is also possible to employ colloidal solutions of manganese compounds in suitable solvents This reaction may also be employed in some cases to the oxidation of other aldehydes to their corresponding acids.

We declare that what we claimis:

1. Process for the manufacture of organic acids from the corresponding aldehydes, comprising oxidizing said aldehydes with oxygen in presence of a manganese compound as catalyst.

2. Process for the manufacture of organic acids from the corresponding aldehydes, comprising oxidizing said aldehydes with oxygen under stirring in presence of a manganese compound as catalyst.

3. Process for the manufacture of acetic.

acid, comprising oxidizing acetaldehyde by a gas containing oxygen in the presence of a manganese compound as catalyst.

4. Process for the manufacture of acetic acid, comprising oxidizing acetaldehyde by a gas containing oxygen under stirring in 1 the mixture.

9. Process of manufacturing acetic acid, comprising oxidizing acetaldehyde with oxygen in the presence of a manganese compound as catalyst and in presence of another metal compound.

10. Process of manufacturing acetic acid, comprising oxidizing acetaldehyde with oxygen at atmospheric pressure in the presence of a manganese compound as catalyst.

11. Process for the manufacture of acetic acid comprising introducing a gas containing oxygen into acetaldehyde containing a manganese compound as catalyst and recovering any acetaldehyde carried over by the unabsorbed gas.

12. Process of manufacturing acetic acid. comprising oxidizing acetaldehyde with oxygen in the presence of a manganese compound as catalyst and distilling the resulting product to free it from any unchanged acetaldehyde and from said manganese compound.

13. Process for manufacturing acetic acid. comprising oxidizing acetaldehyde with oxygen in presence of a solvent for acetaldehyde and in presence of a manganese compound as catalyst.

14. Process for manufacturing acetic acid, comprising oxidizing acetaldehyde with oxygen in presence of acetic acid as solvent and of a manganese compound as catalyst.

15. The process of manufacturing acetic acid which comprises causing acetaldehyde to interact with oxygen at atmospheric pressure and at ordinary temperatures the presence of a manganese compound catalyst.

16. The process for the manufacture of acetic acid, which comprises introducing oxygen into acetaldehyde contained within a water coo-led vessel in the presence of a manganese compound as catalyst, and agitating said acetaldehyde.

17. The process for the manufacture of an organic acid from the corresponding aldehyde, which comprises causing said aldehyde to interact with oxygen in presence of -a manganese compound as catalyst, at ordinary temperatures.

18. The process for the manufacture of acetic acid, which comprises causing acetaldehyde to interact with oxygen in presence of a manganese compound existing in solution as catalyst, at ordinary temperatures.

19. The process of manufacturing acetic acid comprising mixing acetaldehyde with manganese acetate and passing oxygen through the mixture at ordinary temperatures.

In testimony whereof we affix our signatures in presence of two witnesses.

' Witnesses:

Enron BAUM, MARTIN ERHARD. 

